H. Emori et al., SMALL-INTESTINAL ABSORPTION OF BROPIRIMINE IN RATS AND EFFECT OF BILE-SALT ON THE ABSORPTION, Journal of Pharmacy and Pharmacology, 47(6), 1995, pp. 487-492
The intestinal absorption characteristics of a poorly water-soluble dr
ug, bropirimine, were investigated by the in-situ small intestinal loo
p method using male Sprague-Dawley rats. Bropirimine in solution was w
ell absorbed in the overall small intestine, following first-order kin
etics. The rate determining step for the disappearance of bropirimine
from the small intestinal loop after dosing in the suspension was the
dissolution process from suspension. Bropirimine was:solubilized by so
dium glycocholate. The disappearance of bropirimine from the small int
estinal loop was suppressed by sodium glycocholate contained in the so
lution, because of the loss of thermodynamic activity of bropirimine a
fter its involvement in the micellar complex, not by the direct effect
of bile salt on the permeability of intestinal mucosa. The disappeara
nce of bropirimine was also suppressed by sodium glycocholate containe
d in the suspension. The suppression by sodium glycocholate seemed to
be caused by the greater influence of sodium glycocholate on the therm
odynamic activity of bropirimine than on the dissolution from suspensi
on.